Thermostatically operated air valves have been designed for a variety of uses such as actuation of shutters for the radiators of automobiles and trucks.
Such thermostatically operated air valves are actuated at a predetermined temperature, corresponding to that temperature at which commencement of cooling is desired. At temperatures below the actuation temperature, air does not flow from the air supply to the air actuated device.
Generally, such thermostatically operated air valves employ commercially available devices or sensors having a material therein which, upon reaching the desired actuation temperature, expands and pushes outwardly a push rod or pin, which in turn pushes against a valve member which opens and closes air passageways to either communicate or cut-off the air from the air supply to the air actuatable device. Typical of such temperature actuated air valves are those described in U.S. Pat. Nos. 3,006,552, 3,135,495, and 3,313,485.
While satisfactory for some uses, one shortcoming of such devices is that the thermal sensor extends its push rod only a short distance thereby limiting the size of the opening communicating the air supply with the air actuatable device. This shortcoming causes the air to reach the air actuatable device in diminished flow, whereas for many applications it is highly desirable that the air flow be large and immediate.
Therefore, an object of the present invention is to provide a thermostatically operated air valve which provides almost instantaneous communication between the air supply and the air actuatable device through sufficiently large openings that actuation of the air actuatable device is effected rapidly.